How to make a pyramid pop out of a plain piece of paper.
Step 1: Draw a square with a couple of gaps
Step 2: Draw a couple of lines next to the square
Step 3: Repeat the Square and Line
Rectangles are OK, too.
Step 4: And Again
A couple more times should do it.
Step 5: Cut!
Bust out the razor and cut along the lines. Goes much faster if you do all the verticals first, and then do the horizontals.
Step 6: Pull!
Grab the center square and pull it out. Your plain piece of paper is now a funky bit of pop-up pyramidness.
Step 7: Get More Elaborate
If you have a serious case of OCD or a laser cutter you can take a simple idea to some ridiculous extremes.
Step 8: Change Direction
Instead of drawing squares and then lines, try drawing just squares with a 1/4 rotation in each successive square.
In other words, leave a gap on the right and left for the first, the top and bottom for the next, and back and forth and so on.
Step 9: Change Shapes
Here's an example of a circle design with a slight twist to it. It's too subtle to really see here, unfortunately.